A relay device that relays two inner cables is disclosed in Patent Literature (hereinafter, referred to “PTL”) 1. The relay device disclosed in PTL 1 includes: a joint piece which links two inner cables together; a casing having a space in which the joint piece can move; and a lock member which restricts or allows movement of the joint piece. In this relay device, until the two inner cables are linked to the joint piece, the lock member needs to be kept in a lock state in which movement of the joint piece is restricted.
The lock member is partially engaged with slits formed in an outer periphery of the casing, and when pulled up from the casing, the lock member is set to the lock state in which the lock member restricts movement of the joint piece, and when pushed down onto the casing, the lock member is set to an unlock state in which the lock member allows movement of the joint piece.